Flutter - Parameter Type for a Method-CodePudding

I am working a FLUTTER project and need to write a method (or maybe a function). One of the parameters in the method needs to be an expression like:

PlayList videos = videoList[index] as PlayList

Is it possible? If so what type should I should use.

CodePudding user response：

You can achieve what you want, by doing this

void sampleMethod(int playlistIndex){
    PlayList videos = videoList[playlistIndex] as PlayList;
    // do something with videos
  }

Passing PlayList videos = videoList[index] as PlayList directly as parameter is not possible because, in Dart default values of optional parameters must be constants.

In your case, the value of videos depends on [index] which is a changing value.

CodePudding user response：

typedef ProcessCallback = PlayList Function(dynamic, int);

class PlayList {
  String? id;
  PlayList(this.id);
}